In general, most of chemical bond energies of molecules in a gas are 3 eV or more. Even though the gas is merely heated to a high temperature, the molecules are not decomposed. However, when a gas heated to a high temperature is caused to vertically collide with a metal containing an element having a catalytic effect, the gas molecules change their structures. When chemically reactive gas species are heated and caused to collide with a catalyst, the gas species react to make it possible to generate a gas including molecular species different from those of the original gas or having a form different from that of the original gas (to be referred to as a catalyst collision reaction hereinafter).
For example, when, in a vessel containing a ruthenium catalyst, a gas obtained by instantaneously heating methane and water vapor is caused to collide with the ruthenium catalyst, the reaction proceeds to generate hydrogen H2, carbon dioxide CO2, and carbon monoxide CO. This reaction is one example of a catalyst collision reaction. Although water is heated to be vapored, the temperature does not only simply become high, the structure of the water is considered to be changed from polymers (clusters of water) obtained by polymerizing molecules into monomers. The generated monomer gas is estimated to be changed in chemical characteristic and to have an active chemical characteristic different from that of normal water.
In order to industrially use the catalyst collision reaction, a device for instantaneously heating a gas and a low-price compact heating device for causing a gas to collide with a catalyst are required.
Gas heating devices which satisfy the requests are disclosed in documents (see, for example, PTL 1, PTL 2, PTL 3, PTL 4, and PTL 5). These instantaneously-heating devices are hereinafter called heat beam heating devices (HB) here. This principle of HB heating is to cause a gas to collide with a high-temperature wall at a high speed to efficiently perform heat exchange between the wall and the gas.
For that purpose, the speed of a gas is increased in a narrow gas flow path formed on a surface of a heat exchange substrate, and the gas is caused to vertically collide with a flow path wall. Since this flow path wall is electrically heated, heat exchange is caused by this collision.
A film-forming apparatus is disclosed that heats a plurality of gases with the heat beam heating device and grows, on a glass or plastic substrate kept at a temperature lower than the heating temperature, a material which is not able to be grown without heating the substrate to a high temperature that is equal to or higher than its heatproof temperature (see, for example, PTL 5).
The following are related prior art references:
PTL 1: Japanese Unexamined Patent Application, First Publication No. 2013-235945
PTL 2: Japanese Unexamined Patent Application, First Publication No. 2014-59080
PTL 3: Japanese Unexamined Patent Application, First Publication No. 2015-96792
PTL 4: Japanese Unexamined Patent Application, First Publication No. 2015-64132
PTL 5: Japanese Patent Publication No. 5105620